(CNN) – A federal jury has rejected a lawsuit by actor Stephen Baldwin and a New Orleans businessman that claimed actor Kevin Costner and others tricked them out of millions of dollars in a dispute stemming from the 2010 Gulf oil spill, an attorney for Baldwin said Friday.

Baldwin and Spyridon Contogouris had said the fellow actor fooled them into selling their stock in a company that made oil spill cleanup machines the same week that BP placed a $52 million order for the technology.

The decision against Baldwin was made Thursday evening.

“The jury was doing their best to understand everything in a … seemingly complicated issue,” Costner told CNN affiliate WWL.

“They were really smart,” he said; it was “my good luck that they saw the truth of the story.”

Baldwin’s attorney, James Cobb, said he was disappointed with the decision.

“We believe we put on a case sufficient for the jury to find in our favor,” he said. “The jury found the other way.”

The oil separation technology was developed in the 1990s by a company created by Costner, but Baldwin became involved while in New Orleans to produce a documentary about the Deepwater Horizon spill in the Gulf of Mexico in May 2010.

Baldwin and Contogouris decided to sell their stock soon after getting it because of differences with other shareholders, according to the lawsuit. They signed an agreement to sell their shares to Patrick Smith, who then transferred them to a company partly owned by Costner, on June 11, 2010.

BP announced on June 15, 2010, it would lease 32 machines from the company.

If Smith and Costner had told them BP was placing a huge order, they would not have sold, the suit said.

The 10% of the company that Baldwin sold for $500,000 should have been worth $3.8 million, while the 28% stake sold by Contogouris for $1.4 million was worth $10.6 million, the suit said.

Lawyers for Costner and Smith say Baldwin and Contogouris sold their stock “with eyes wide open, to get out of a soured business relationship and to invest in other ventures.”

They knew that BP might place the order, a defense filing said. It was widely reported in the news and Costner testified about it to Congress two days before the stock sale.